Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
  • F01K25/00—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for
  • F01K25/08—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for using special vapours
  • F01K25/10—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for using special vapours the vapours being cold, e.g. ammonia, carbon dioxide, ether
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02G—HOT GAS OR COMBUSTION-PRODUCT POSITIVE-DISPLACEMENT ENGINE PLANTS; USE OF WASTE HEAT OF COMBUSTION ENGINES; NOT OTHERWISE PROVIDED FOR
  • F02G5/00—Profiting from waste heat of combustion engines, not otherwise provided for
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
  • F01K25/00—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for
  • F01K25/06—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for using mixtures of different fluids
  • F01K25/065—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for using mixtures of different fluids with an absorption fluid remaining at least partly in the liquid state, e.g. water for ammonia
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
  • F01K25/00—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for
  • F01K25/08—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for using special vapours
  • F01K25/10—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for using special vapours the vapours being cold, e.g. ammonia, carbon dioxide, ether
  • F01K25/106—Ammonia
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
  • F01K7/00—Steam engine plants characterised by the use of specific types of engine; Plants or engines characterised by their use of special steam systems, cycles or processes; Control means specially adapted for such systems, cycles or processes; Use of withdrawn or exhaust steam for feed-water heating
  • F01K7/16—Steam engine plants characterised by the use of specific types of engine; Plants or engines characterised by their use of special steam systems, cycles or processes; Control means specially adapted for such systems, cycles or processes; Use of withdrawn or exhaust steam for feed-water heating the engines being only of turbine type
  • F01K7/22—Steam engine plants characterised by the use of specific types of engine; Plants or engines characterised by their use of special steam systems, cycles or processes; Control means specially adapted for such systems, cycles or processes; Use of withdrawn or exhaust steam for feed-water heating the engines being only of turbine type the turbines having inter-stage steam heating
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
  • F01K9/00—Plants characterised by condensers arranged or modified to co-operate with the engines
  • F01K9/003—Plants characterised by condensers arranged or modified to co-operate with the engines condenser cooling circuits
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B30/00—Heat pumps
  • F25B30/02—Heat pumps of the compression type

Definitions

• the invention relates to a system and method for recycling thermal heat or energy output from an energy extraction device, such as a turbine. More particularly, this invention relates to heat engines and plants for producing mechanical work or other forms of energy. Even more particularly, this invention relates to power generation apparatus and method of producing electrical energy from a variety of energy sources of relatively low to high temperatures which usually operates in a closed thermodynamic cycle.
• the invention also relates to a system and method for operating a refrigeration cycle of a heat pump.
• Efficiency of the power plants operating on Rankine cycle is generally low and particularly of those plants utilising lower level (temperature) energies, and is also much lower than the corresponding theoretical Carnot cycle.
• the current operating conventional power plants have been continuously developed, are highly reliable and produce continuous electrical power, many associated adverse factors and environmental requirements result in higher initial specific investment cost per KW power.
• the inventor has appreciated that it is advantageous to provide a heat engine system which is capable to operate at a lower working medium vaporisation temperature (such as ammonia) than conventional power generating plants operating on Rankine Cycle which operate mainly on water as the working medium, but under similar or even higher vapour and gases pressures to the turbines.
• a working medium vaporisation temperature such as ammonia
• the heat engine is also able to operate with minimum requirement for rejection of condensation latent heat of the spent working medium to the outside environment with cooling agents or preferably that the heat engine can operate without the need for rejection of condensation latent heat of the condensing step of the conventional power cycles to the outside environment.
• Embodiments of the invention seek to provide a heat engine system which can combine some of the advantageous principles and criteria to generate power, while the ultimate aim and goal of the inventor is to improve efficiency of the heat engines and produce more work and power from the energy used to operate power plants.
• Embodiments of the invention can utilise various sources of thermal energy from high temperatures of over 673 K (400 °C), which are obtained from combustion of the fossil fuels, to the low level temperatures, such as that of geothermal energy of about 403 K (130 °C) and power plants waste energy (condensation) or sea water or river water of any temperature of -say over 5 °C.
• embodiments of the invention may include facilities which can process the induced thermal energy and generate power and facilities which can partially or fully preserve and recycle the latent heat of condensation of the working fluid within the boundaries of the thermodynamic cycle of the proposed heat engine. The recycled heat can then supplement the induced energy to vaporise more working medium to be fed to the power turbine and generate further power and improve efficiency of the novel heat engine.
• a system for recycling heat or energy of a working medium of a heat engine for producing mechanical work or other forms of energy comprises heat exchanging means (204) for transferring heat from a working medium output from an energy extraction device (202) to a heating agent to vaporise the heating agent; second heat exchanging means (240) for transferring further heat to the vaporised heating agent; compression means (231 ) coupled to the second heat exchanging means (240) arranged to compress the further- heated heating agent; and third heat exchanging means (21 1 ) for transferring heat from the compressed heating agent to the working medium.
• the second heat exchanging means may transfer further heat to the vaporised heating agent from heating agent output from the first heat exchanging means.
• heat exchangers are used.
• each heat exchanger has a first input, a second input, a first output and a second output.
• Embodiments of the invention find application as a heat engine for producing mechanical work comprising the energy recycling system previously described.
• the heat engine may comprise a turbine, such as a single or multi-stage turbine for producing mechanical work.
• the working medium output from the energy extraction device may be referred to as a spent working medium i.e. it comprises only a vapour or a vapour-liquid phase.
• the further heating of the vaporised heating agent may be referred to as to superheating the heating agent.
• a single heat exchanging means may be provided rather than having a heat exchanging means and second heat exchanging means.
• a high performance heat pump which may use a heating agent such as n-Octane.
• the heating agent may be a refrigerant.
• Heat pumps embodying the invention may have an improved Coefficient of Performance (CoP) compared to prior art heat pumps.
• CoP Coefficient of Performance
• the Coefficient of Performance may be defined as the quantity of energy delivered to the hot reservoir per unit of work input.
• Embodiments of the invention may have a CoP, for example, of about 8 compared to conventional heat pumps which may have a CoP of about 1 .5 under similar conditions of temperature.
• Heat engines embodying the invention may have efficiencies in the range of 55% to 57% compared with conventional engines having efficiencies of up to 45%.
• the working fluid used by embodiments of the invention may be any material with suitable thermodynamic properties, such as ammonia, ammonia-water mixtures, etc.
• the energy preserving and recycling materials (heating agents) can also be any material with suitable thermodynamic properties, such as n-octane, n-heptane, iso-octane, amylamine, butylformate, etc.
• Pure ammonia and Ammonia-water mixtures have suitable thermodynamic properties and have been selected as a working fluid (as an example) for embodiments of invention, while n-octane has suitable thermodynamic properties and been selected as the heating agent fluid (also as an example) for the energy preservation and recycling system embodying the invention.
• two fluids and two operation loops for energy preservation and recycling are utilized.
• some embodiments recycle the entire energy of the spent working fluid by absorbing the energy of the spent working medium, even at very low temperatures such as below 7 °C and preferably by lifting the temperature of the absorbed waste energy to a very high level of the hot temperature reservoir to be used, preferably repeatedly, to vaporized working medium and generate power.
• Some embodiments comprise a heat exchanger 256 and absorb energy from very low temperature level reservoirs sources, into the system and lift its temperature to the high temperature reservoir and generate power from it.
• Some embodiments superheat the heating agent prior to feeding to the compressor, to minimize work or power requirements per unit weight of heating agent.
• Embodiments of the invention may be applicable to any system which generates waste heat, and will recycle and preserve the waste heat.
• Embodiments of the invention may include two integrated loops, which may comprise a work and preferably power producing loop; and energy recycling and preservation loop.
• Embodiments of the invention may therefore recycle waste energy thereby preserving it within a thermodynamic cycle.
• the main characteristic features and aspects of the present invention are that, it comprises heat preservation and recycling system which absorbs latent heat of condensation of the waste working medium from the work producing device and increase its temperature and recycle the absorbed heat back into the heat engine, this achieved by vaporizing heating agent in a heat exchanger where it absorbs the released latent heat of condensation of the waste working medium.
• the vaporised heating agent is preferably superheated and fed to a compressor, which compresses it and increases the corresponding temperature of the heating agent vapours.
• the high temperature heating agent is fed to a heat exchanger where it heats and vaporises the pressurised liquid working medium.
• the recycled heat of the waste working medium is added to the fresh induced heat to vaporize more working medium and produce further mechanical work and improve efficiency of the system.
• the heat preserving and recycling system operates in a closed loop (first loop) and repeats the heat recycling process in a continuous manner.
• the vaporized working medium from both fresh and recycled energy sources is preferably further superheated and fed to the mechanical work producing devices where it expands and produces mechanical work, and becomes the waste working medium at the outlet from the device.
• the wasted working medium is then condensed in a heat exchanger by vaporizing liquid heating agent, and the working medium condensate is pressurized by a pump to be fed back to the heat exchanger where it is heated and vaporized by the recycled and fresh heat energy and repeats the cycle. Therefore the mechanical work producing system also operates in a closed loop (second loop).
• the proposed novel mechanical work (and power) producing heat engine therefore, includes operating facilities for at least two (2) operating closed loops, which can receive energy from outside and interact with each other in a manner to form a closed thermodynamic cycle, and generate power, and they are:
• each of these two loops can in turn, comprise more than one full operating closed sub-loops, which interact internally with each other to perform the ultimate function and role of the said main loop.
• Each loop or sub-loop can utilise a single component or multi component material as its working fluid (medium) to perform and achieve the aim of power generation or energy preservation recycling and.
• thermodynamic properties of the heating agents for energy preservation and recycling loop can be contrasting with the suitable properties for working mediums for mechanical work and power generation, as they are required to perform different functions and are explained in sections of this report.
• Each loop has joint facilities with the other loop mainly to exchange thermal energy between the working medium fluid and energy preservation and recycling heating agent, and some specific dedicated belonging facilities to perform the other required specific function of that loop, and is explained in the detailed description section.
• a heat engine for producing mechanical work or other forms of energy comprising means for one stage or progressive cooling and condensing to a liquid, vapours of a spent (waste) working medium (WM) produced by the engine as a result of the production of mechanical work.
• Spent working medium is also produced from the turbine of the energy preservation and recycling system compressor (heating agent) and superheating turbine and high pressure liquid ammonia pump turbine, if used. Operating conditions of all these stream of spent ammonia are controlled so that they can be mixed together at a specific pressure for subsequent processing. Condensation of the spent ammonia streams is conducted in a manner so that minimum or preferably no rejection of latent heat energy to outside environment of the operating thermodynamic cycle is involved. This is achieved by using and forcing the liquid heating agent n-octane to vaporize at the other side of the heat exchange surface of the condenser and absorb the latent heat of condensation of working medium.
• the condensed working medium is fed to the hold tank, from where it is withdrawn and pressurized by a pump to the required pressure of the high pressure high temperature working medium at the inlet to the power generation turbine Pi .
• the pressurized liquid working medium is progressively heated and partially or fully vaporized in a series of heat exchangers at a significantly higher temperature by the effect of latent heat of condensation of the counter current direction vapours of n- octane, the heating agent of the energy preservation and recycling loop (heat pump).
• Vapour-liquid mixture of the working medium if not fully vaporized in the heat exchangers, is then fed to a flash separation tank or column to separate high pressure and high temperature vapours from the liquid. Vaporization of the required amount of working medium is completed in the flash separation column by means of a circulation loop of a pump and reboiler, with internal or external energy source. Vaporization temperature of the high pressure single component working medium in the separation flash tank is constant and depends only on the pre-selected vaporization pressure of the working medium (ammonia). However, the top vaporization temperature of the multi component working medium, such as ammonia-water mixture, depends on the selected pressure in the separation tank and the lean solvent concentration at the bottom of the separation column (tank).
• the separated higher pressure and higher temperature working medium ammonia vapour may further be superheated in a heat exchanger (super heater) to improve the overall efficiency of the novel thermodynamic "Atalla Harwen Cycle".
• the superheated high pressure and high temperature working medium vapour is split into two or more streams.
• One main stream is fed to the power turbine to extract mechanical work or other forms of energy and as a result, produce the low pressure low temperature spent working medium and repeat the cycle.
• the other main stream is fed to the turbine of the energy preservation and recycling system compressor (heat pump), as the source of providing the required mechanical power, to operate the energy preservation and recycling loop.
• Other streams can also be used: One such stream for the superheating boosting compressor; another stream to operate the working medium liquid high pressure pump, or other pumps and booster compressors, etc.
• the high pressure and high temperature working medium is fully vaporized in the heat exchanger upstream of the flash separation tank then, it can then by-pass the flash separation column (tank) and be fed directly to the super heater and split to the different turbines and pumps as explained above.
• Condensation of the saturated spent working medium vapours is accomplished in the designated heat exchanger (condenser) of the spent working medium by utilising an energy preservation and recycling system loop (heat pump) with a suitable heating agent (in this case n-octane).
• the energy preservation and recycling system is arranged to allow vaporization of the liquid and cold heating agent n-octane in condenser of the spent working medium, under selected low pressure and temperature of the cold reservoir.
• the heating agent vaporizes and absorbs latent heat of condensation from the condensing working medium vapours on the hot side of the heat exchange surface.
• the vaporized heating agent n-octane is superheated in a super heater to a sufficiently high temperature, so that when compressed in the system compressor to the required high pressure will preferably not condense inside the compressor.
• Superheating of the low pressure heating agent in the said super heater is accomplished by utilizing several vapours and liquids streams of higher temperature of the compressed same heating agent n-octane, and the combined stream of the liquid heating agent is cooled down to the lowest possible temperature at the outlet from the super heater.
• the superheated low pressure heating agent is then compressed by the energy preservation and recycling system compressor in one stage or multi stages, to a sufficiently higher pr-selected pressure, which also raises condensation saturation temperature of the pressurised heating agent n-octane to a convenient level of the hot reservoir.
• the high condensation saturation temperature of the energy preserving and recycling agent is such that it is suitable to be used in another heat exchanger or vaporizer, to heat and vaporize as much as possible of the pressurized and heated liquid working medium prior to feeding to the flash separation tank. If the working medium is fully vaporized in the said heat exchanger (vaporiser), it can be directly fed to the super heater downstream of the flash separation tank.
• the condensed heating agent in the working medium vaporizer is a hot condensate and is then cooled to the lowest possible temperature by heating up the counter current flowing and pressurized cold liquid working medium ammonia from the pump, downstream of the working medium ammonia hold tank.
• the cooled heating agent streams from both the super heater of the low pressure vapours n-octane and liquid working medium ammonia heater are fed to the heating agent n-octane hold tank.
• the cold heating agent is withdrawn from the hold tank, depressurized and fed to the spent working medium condenser to be vaporized again and repeat the energy preservation and recycling system loop.
• the lower temperature of the cooled returned heating agent to the hold tank prior to de-pressurization and vaporization stage improves both system efficiency and Coefficient of Performance (COP) of the energy preservation and recycling system compressor (heat pump).
• COP Coefficient of Performance
• a stream of the high pressure and high temperature superheated working medium is used to drive a turbine which in turn operates the energy preservation and recycling system compressor. It is also possible however, that the entire amount of superheated working medium ammonia is fed to the power turbine to generate electricity and then use electrical motor to operate the energy preservation and recycling system (compressor). Such arrangement will result in additional losses in the form of efficiency of the electric motor and other associated heating losses.
• Conditions of the spent working medium ammonia from the energy preservation and recycling system compressor drive turbine are controlled to be similar to conditions of the spent working medium ammonia from the power turbine and both spent materials are mixed for condensation in a joint condenser.
• the hot and high pressure lean solvent is withdrawn from the bottom of the flash separation tank and is cooled in a heat exchanger by a portion of the cold rich solvent in the counter current direction through the said heat exchanger.
• the cooled lean solvent is then depressurized and mixed with the low pressure spent working medium vapours, which are then fully condensed by the effect of vaporizing heating agent in the condenser, as in the case with single component working medium.
• the condensed liquid and cold working medium ammonia has been pressurised by the pump, ready to be heated and requires vaporization. There is then provided the vaporized and pressurized energy preservation heating agent n-octane with a suitable higher temperature, and is ready to condense and release its latent heat of condensation to vaporize the pressurized and heated working medium at the opposite side of heat exchange surface and at a little lower temperature.
• Flow rates of the working medium ammonia is set for the specified power generation capacity of the heat engine, for example at one kg/s, and the flow rate of the heating agent n-octane is controlled in each piece of joint equipment in a manner to ensure the supply or withdrawal of the required thermal energy by the working medium stream of one kg/s in the opposite side of the heat exchange, and also to ensure the minimal or preferably, no need for an outside cooling agents (sea water or river water) to reject energy to outside of the operation cycle.
• an outside cooling agents suction water or river water
• the scheme can minimize and/or preferably avoid the need for the spent working medium condensation (condenser) with an outside cooling agent, which if utilised, results in significant energy losses to the external cooling agent as required by systems operating according to the prior art.
• the spent working medium ammonia produced by the engine as a result of power generation is usually a gaseous spent (waste) working medium.
• the waste (spent) working medium ammonia may be partially condensed to liquid and mainly stays as gaseous.
• Embodiments of the invention can operate at a lower temperature mode and in a less harsh environment than that of conventional power plants operating on Rankine Cycle. Furthermore, conventional power plants may be readily modified to include a heat engine according to embodiments of the invention.
• Figure 1 shows a schematic diagram of a thermodynamic cycle used in a conventional Rankine power plant
• FIG. 2 shows a schematic diagram of a thermodynamic cycle used in a conventional 'Kalina' power plant
• FIG. 3 shows schematic diagram of thermodynamic cycle and the novel heat engine with single component working medium system - "Atalla Harwen Cycle”;
• Figure 4 shows schematic diagram of thermodynamic cycle and the novel heat engine with single component working medium system -"Atalla Harwen Cycle";
• FIG. 5 shows schematic diagram of thermodynamic cycle and the novel heat engine with a binary component working medium system - "Atalla Harwen M Cycle";
• Figure 6 shows schematic diagram of the novel heat engine “Atalla Harwen Cycle” with single component working medium system and comprising two sub-loops of the energy preservation system ;
• Figure 7 shows schematic diagram of thermodynamic cycle and the novel heat engine with a binary or single component working medium system - "Atalla Harwen Cycle” plant and comprising a heating agent loop to provide energy for the separation tank reboiler;
• Figure 8 shows schematic diagram of thermodynamic cycle and the novel heat engine with a binary or single component working medium system - "Atalla Harwen Cycle” plant and comprising a super heater compressor system;
• Figure 9 shows schematic diagram of the novel heat engine “Atalla Harwen Cycle” with a binary component working medium and comprising a dual liquid pump for pumping working medium
• Figure 10 shows schematic diagram of the novel heat engine “Atalla Harwen Cycle” with single component working medium system (ammonia) and comprising a booster compressor for the vent ammonia from the hold tank 206;
• Figure 1 1 shows schematic diagram of the novel heat engine “Atalla Harwen Cycle” with single component working medium system (ammonia), and comprising a direct fired super heater
• Figure 12 shows schematic diagram of the novel heat engine “Atalla Harwen Cycle” with single component working medium system (ammonia), and comprising a direct fired heater (boiler) and steam generated super heater and/or a source of outside energy into the system;
• Figure 13 shows schematic diagram of thermodynamic cycle and the novel heat engine with single component working medium system - "Atalla Harwen Cycle” plant and comprising a low temperature reservoir energy source and vaporizer and/or condenser;
• Figure 14 shows multi stage (4 stages) compression of heating agent (n-Octane) showing condensate withdrawal at the end of stages with knock-out tanks;
• FIG. 15 shows Temperature-Entropy (T-s) diagram of Ammonia and areas of the material physical phase statuses
• Figure 16 shows Temperature-Entropy (T-s) diagram of Ammonia showing steps of a power generation loop with superheating of high pressure ammonia and isentropic expansion;
• FIG. 17 shows Temperature-Entropy (T-s) diagram of Ammonia showing steps of a power generation loop with expansion of high pressure ammonia from the saturation point C;
• FIG. 18 shows Temperature-Entropy (T-s) diagram of Ammonia showing steps of a power generation loop with expansion of high pressure ammonia from the saturation point C;
• FIG 19 shows Temperature-Entropy (T-s) diagram of Ammonia showing steps of a power generation loop with superheating of the high pressure vaporized ammonia with two stage ammonia expansions and interim superheating;
• FIG. 20 shows Temperature-Entropy (T- s) diagram of n-Octane and areas of the material physical phase statuses;
• FIG. 21 shows Temperature-Entropy (T-s) diagram of n-Octane showing steps of the energy preservation loop with single stage compression of n-octane;
• FIG. 22 shows Temperature-Entropy (T-s) diagram of n-Octane showing steps of the energy preservation loop with single stage of n-octane expansion from pressure of point C to pressure of point B;
• FIG. 23 shows Temperature-Entropy (T-s) diagram of n-Octane showing steps of the energy preservation loop with single stage compression of n-octane from the saturation state at point B, and representation of energy constituents by corresponding areas;
• FIG. 24 shows Temperature-Entropy (T-s) diagram of n-Octane showing steps of the energy preservation loop with Multi stage (4 stages) compression of n-octane from the saturation state at point B and withdrawal of condensate at the end of each stage;
• FIG. 25 shows Temperature-Entropy (T-s) diagram of n-Octane showing steps of the energy preservation loop with infinite stages of compression of n-octane from the saturation state at point B and withdrawal of condensate at the end of each stage;
• FIG. 26 shows Temperature-Entropy (T-s) diagram of n-Octane showing steps of the energy preservation loop with superheating of n-octane prior to feeding to the compressor;
• FIG. 27 shows Temperature-Entropy (T-s) diagram of n-Octane showing steps of the energy preservation loop with superheating of n-octane prior to feeding to the compressor;
• FIG. 28 shows Temperature-Entropy (T-s) diagram of n-Octane showing steps of the energy preservation loop with partially superheating of n-octane prior to feeding to the compressor;
• Figure 29 shows Temperature-Entropy (T-s) diagram of n-Octane showing steps of the energy preservation loop with superheating of n-octane prior to feeding to the compressor;
• FIG 30 shows Temperature-Entropy (T-s) diagram of n-Octane showing steps of the energy preservation loop with superheating of n-octane prior to feeding to the compressor; and
• Figure 31 shows superimposed Temperature-entropy (T-s) diagram of n-octane (as the heating agent) and ammonia (as the working medium) to form the integrated "Atalla Harwen Cycle".
• figure 1 represents the typical conventional power generation unit operating on Rankine cycle.
• the main steps performed by a conventional power generation plant are:
• Liquid water 105b is withdrawn from the hold tank 105 and is pumped by a pump 106 from a low pressure to a sufficiently high pressure by inputting energy.
• the high pressure liquid water enters a boiler 107 and is vaporized under high pressure and at high but constant saturation temperature by inputting energy released from the burnt fuel 108.
• Water Vapours expansion in the turbines can be in one stage or in several, but mostly 2, stages.
• the lower pressure and lower temperature spent water vapour 103 leaving the turbine 102 which typically at this stage has a temperature of 323 to 373 K (50 to 100 °C), and a pressure of 0.025 to 0.1 MPa (0.25 to 1 .0 bar abs), is then condensed to a liquid in condenser 104, resulting in a phase change and energy rejection or loss to the cooling medium 104b (sea water).
• water vapour condenses from a volume of about 1 .7 to 5.0 m 3 /kg to a liquid volume of 0.001 m 3 /kg under pressure of 0.10 MPa (1.0 bar abs), and this process results in the loss of the latent energy of vaporization of about 2300 kJ/kg of water (560 kcal/kg) to the returned sea water 104b.
• This is a significant amount of lost energy to the outside environment (coolant) and results in lower efficiencies of the power plants operating on Rankine cycle, which are typically between 33% to 40%, and for super high pressure systems, efficiency can be up to 45%.
• FIG. 3 it represents the typical conventional power plant operating on Kalina cycle, operating with an ammonia-water mixture as the working medium.
• the main steps performed by a conventional power generation plant operating on Kalina cycle are similar to those of Rankine cycle, in terms of:
• Kalina cycle has a higher turbine 102a back pressure of over 0.5 MPa (5 bar), to allow for condensation of ammonia-water working medium mixture vapours in the sea water condenser 104a,
• Kalina cycle includes recycling of the hot lean solvent 107ca from separator 107ba, which is cooled, depressurized and then mixed with the spent working medium 103a, and the vapour-liquid mixture is then fed to the sea water condenser (heat exchanger) 104a.
• the process involves cooling the recycled lean solvent to the sea water condenser temperature with fully condensed working medium vapours and the mixture becomes a rich solvent which is heated again to the top temperature of the high pressure vapours leaving the boiler,
• Embodiments of the two variations of the proposed novel heat engine 200 and 300 are similar in most aspects of construction and operation, but also have minor differences, which are mentioned as applicable.
• the main embodiment aspects and features of the proposed power cycle (plant) for either type of working mediums, is that the involved heat engine comprises two (2) individual but actively interacting closed loops, which are
• any of these two loops can include one or more sup-loops which can be similar or different in configuration.
• Sub-loops of each main loop interact with each other to perform the ultimate role and functions of the corresponding main loop.
• This embodiment is particularly applicable to the energy preservation and recycling loop and less likely for power generation loop. Characteristics features and performance of the interacting sub-loops and main loops to generate net power are made possible by the careful selection of suitable materials (operation fluids), techno-mechanical facilities and operation conditions of both main loops and sub-loops, including:
• Working mediums which are suitable to be used in the power generation loop of the novel system can be:
• - Water is used mainly as the working medium in Rankine cycle plants, where fuel burning temperature can reach very high levels suitable for vaporization of water under high pressures and condensation temperature of the spent water vapours from the turbines, is sufficiently high to allow the use of sea water or river water or atmospheric air as the coolants,
• Multi component fluid for working medium which comprises a mixture of two or more low and high boiling materials with favourable thermodynamic properties and wide range of inter-solubility, such as ammonia-water mixture (also used in Kalina cycle),
• Multi component fluid for working medium which comprises a mixture of various hydrocarbons, various freons, or other materials
• difference between the boiling temperature of the lower boiling working medium component (WM) and solvent is preferably more than 100 degrees K.
• Energy preservation agents which are suitable to be used in this invention for the energy preserving and recycling loop may be any material with suitable thermodynamic properties, such as:
• thermodynamic properties of these energy preserving and recycling agents are highly desired and are carefully selected to be contrasting with the same thermodynamic properties of working mediums of the power loop (ammonia and water vapours).
• value of the exponent (k) in the adiabatic equation of state of gases is very important:
• P - is the gas pressure at the start of intended process
• V - is the gas volume at the start of intended process
• the adiabatic expansion exponent k is expressed in terms of ratio of the specific heats of gas under constant pressure (Cp) to specific heat of the said gas under constant volume (C v ), as follows:
• Embodiments of the heat engine 200 or 300 comprise a mechanical work and power generation loop and an energy preservation and recycling loop
• the power generation Loop comprises dedicated means 202 or 302 for converting potential energy of the vapours pressure of expanding working medium to mechanical work, means 206 or 306 for storing (holding) condensed liquid working medium, means 207 or 307 for pumping and pressurizing liquid working medium, means 213 or 313 for the flash separation of the high pressure and high temperature working medium vapours 214 or 314, from the liquid working medium 216 or lean solvent 316, means 215 or 315 for heat exchange (super heating), means for conveying the high pressure and high temperature working medium 208 or 308, or the spent (waste) working medium 203 or 303, from one component of the heat engine 200 or 300, to another component of the same heat engine 200 or 300, and in the case of multi component working medium heat engine 300, comprises further means of heat exchange 319, embodying the invention, and the mechanical work and power generation loop of the heat engine 200 or 300 further comprises joint means with energy preservation
• a line, or pipe, or tube or other means for conveying the working medium vapours and liquid connects the turbines 202 and 246 or 302 and 346 to the working medium hold tank 206 or 306 and separation flash tank 213 or 313 respectively, via various heat exchangers.
• the heat engine 200 or 300 further comprises an energy preservation and recycling loop which comprises dedicated means 240 or 340 for superheating the vaporised low pressure heating agent, means 231 or 331 for compressing the superheated heating agent, means 235 or 335 for receiving and storing the condensed heating agent, and the energy preservation and recycling loop of the heat engine 200 or 300 further comprises joint means with power generation loop for the heat exchange 204, 209 and, 21 1 and 202b or 304, 309, 31 1 and 302b and means 246 or 346 for providing mechanical work and drive for the compressor 231 or 331 .
• a line, or pipe, or tube or other means for conveying the heating agent vapours and liquid connects the compressor 231 or 331 to the heating agent hold tank 235 or 335 via various heat exchangers
• a line, or pipe, or tube or other means for conveying the working medium vapours connects the turbines 246 or 346 to the working medium line from the heat exchange 215 or 315 to the spent working medium vapours and liquid line from the turbine 202 or 302 respectively
• the heat engines 200 comprises facilities of both the mechanical work and power generation loop and energy preservation and recycling loop
• the power generation loop comprises a mixer 203a which is arranged to receive streams of the low pressure and low temperature spent working medium (in this example ammonia) 203, and 247 from the turbines 202 and 246 and any other streams of the spent working mediums such as the vent vapours and booster compressors turbine from alternative embodiments which are explained later in this section, and the combined stream of the spent working medium 203b is fed to heat exchanger- condenser 204.
• Condensation temperature of the working medium vapours (pure ammonia) depends on its condensation saturation pressure in the condenser 204.
• condensation temperature of pure ammonia is about 280 K (7 °C).
• the condensed working medium 205 is fed to the hold tank 206, and the volume of the hold tank 206 is sufficiently large to store the necessary quantities of the working medium for the smooth and continuous operation of the novel system.
• Liquid working medium ammonia 206a is withdrawn from the hold tank 206, pumped by the pump 207 and pressurized in one stage or several stages to the required pressure (for example to 7.25 MPa - 72.5 bar) which is suitable for the selected vapour pressure of the working medium ammonia at the inlet to turbines 202 and 246, which is selected at pressure of 7.135 MPa (71 .35 bar) and allow for the flow and mechanical losses.
• the cold working medium is heated and partially or fully vaporized by the effect of hot streams of the heating agent in the heat exchangers 209 and 21 1 , and is fed to the separation flash tank 213.
• Other arrangements of the heat exchanger can also be made which can perform same or similar heat exchange functions. If for example the working medium is fully vaporized in the heat exchanger 21 1 , it can by-pass the flash separation tank and be fed directly to the super heater 215.
• the separation flash tank 213 is also provided with a liquid circulation pump 220 and reboiler 221 to circulate liquid working medium through the reboiler which provides the necessary external or internal energy for vaporization of the required additional amount of working medium to ensure supply of the necessary quantities of the working medium for operation of the turbines 202 and 246.
• Top temperature of vaporization of the high pressure working medium in the separation tank which is also temperature of the liquid working medium at the bottom of the separation tank, depends on constant pressure of vaporization (saturation) of the working medium in the separation flash tank 213. For example if the pressure of vaporization of the working medium "ammonia" inside the separation flash tank is selected and set at 7.135 MPa (71 .35 bar), the corresponding vaporization constant temperature of ammonia will be about 380 K (107 °C).
• volume of the separation flash tank (column) 213 is sufficiently large to provide suitable space for the ready flashing and separation of the vaporized working medium from the liquid single component or multi component working medium.
• the vaporized saturated working medium (ammonia) 214 at high pressure and high temperature leaves the separation tank from a suitable exit and can further be superheated (optionally but preferably) in the heat exchanger 215 by the effect of a low, medium or high pressure steam 216, or internal higher temperature energy source.
• the high pressure and high temperature superheated working medium (ammonia) 214a at the outlet from the super heater 215 is divided into two main streams, which are:
• Stream 201 of the superheated working medium is fed to the turbines 202, where it is allowed to expand and produce mechanical work or other forms of energy, which includes the net energy output of the novel system power plants,
• Stream 245 of the superheated working medium is fed to the turbine 246, to provide the required power (mechanical work) which operates the energy preservation and recycling system compressor 231 ,
• streams of the high pressure and high temperature superheated working medium 214a at the outlet from the super heater 215, can also be provided to operate the high pressure liquid working medium ammonia pump 207, or for further boosting and elevation of temperature of a portion of the energy preserving agent from stream 232, or others.
• these streams are expected to be much smaller than the said two main streams and spent working medium from those streams is added to the spent working medium from the turbines 202 and 246 for condensation in the heat exchanger 204, and repeating the mechanical work and power generation loop.
• the gaseous working medium ammonia 201 entering the turbine 202 is usually a high pressure gas having typical pressure Pi of above 7.135 MPa (71 .35 bar) and a temperature of above 400 K (127 °C). Any other suitable pressure and temperature of the working medium can be selected at the inlet to the turbines 202 and 246, which depend on many factors and considerations of specific conditions of each case.
• the gaseous working medium ammonia is allowed to undergo isentropic expansion in the turbine 202 under controlled conditions, and provides rotational mechanical work, or other types of mechanical work, which may be used to generate electrical power in a generator 202a, or perform other types of work.
• the spent working medium ammonia exits the turbine 202 under significantly reduced but controlled pressure P 2 and at a corresponding lower temperature of T 2 .
• P 2 the outlet pressure
• T 2 the corresponding lower temperature of T 2 .
• the outlet pressure (back pressure) from the turbine 202 is selected at 0.55077 MPa (5.5077 bar)
• the corresponding saturation temperature of the spent working medium will be about 280 K (7.0 °C).
• Working medium stream 245 undergoes similar conditions when fed to turbine 246 and provides mechanical work for the energy preservation compressor 231. Any other suitable back pressure of the spent working medium can be selected at the outlet of the turbines 202 and 246, which depend on many factors, and will determine the corresponding outlet temperature of the working medium.
• Turbines 202 and 246 can be of one or more stages of working medium expansion, and in this particular case it is selected of two stage expansions with interim superheating.
• high pressure and superheated high temperature ammonia is expanded from 71 .35 bar to 25 bar and exits the first stage 201 a which is still at high pressure. It is then fed to the super heater 202b to be superheated again by a stream of the hot vapours of the heating agent stream.
• the interim super heated ammonia is then fed to the second stage of the turbine 202 and is expanded to the final spent working medium 203 which exits the turbine 202 under significantly reduced but controlled pressure P 2 and at a corresponding lower temperature of T 2 , As mentioned above.
• Conditions of the spent working medium from the outlet of turbine 246 are controlled and are preferably the same as those from turbine 202, so that the two streams can be joined again.
• the spent working medium streams from turbines 202 and 246 (and others if applied) are mixed in the mixer 203a and the combined stream 203b, is transferred again to the heat exchanger/condenser 304 to be condensed 205, sent to the working medium hold tank 206, to be fed to the high pressure pump 207 and repeat the power generation loop (internal cycle). .
• the heat engine 200 further comprises an energy preservation and recycling system (based on heat pump principle) with a compressor 231 driven by an electric motor or preferably driven by a turbine 246 which is operated by the high pressure working medium to provide the required mechanical work.
• Compressor 231 can be one stage or multi stages and receives the low pressure low temperature vaporized heating agent (in this example n-octane) 230 from the heat exchanger (super heater) 240, and compresses it to a suitable high pressure at the outlet of the compressor, stream 232.
• n-octane in this example n-octane
• Pressurisation level of the energy preservation and recycling heating agent is selected in a manner so that it will increase the corresponding condensation saturation temperature of the pressurized n-octane to a level, when it is condensed at the selected high pressure, the released condensation latent heat energy of the heating agent, is suitable for use in the heat exchanger 21 1 , to heat and partially or fully vaporize the high pressure working medium (ammonia) 210 in the heat exchanger 21 1 .
• the pressurized heating agent n-octane 232 at the outlet from the compressor 231 is divided into several streams which are used in different parts of the heat engine 200 for different purposes, and they are (in this particular example):
• Condensed and hot heating agent (n- octane) 233a is fed to the heat exchanger 209 and is cooled in one stage or progressively, to the lowest possible temperature, by the effect of the counter flowing pressurized and cold liquid working medium ammonia 208 on the other side of the heat exchange surface, to improve efficiency and 'Coefficient of Performance (COP)' of the energy preservation and recycling compressor (heat pump principle).
• the cooled heating agent 234 from the heat exchanger 209 is fed to the heating agent hold tank 235.
• Heating agent stream 232b is fed to the super heater 202b to superheat the partially expanded working medium ammonia 201 a from 1 st stage of turbine 202.
• heating agent 232b condenses (changes phase to liquid), and releases its latent heat to be used for super heating the partially expanded working medium ammonia 201 a (interim heating in the heat exchanger 202b) and the superheated ammonia 201 b is fed back to the 2 nd stage of turbine 202.
• the condensed heating agent 232e which is at the saturation high temperature is mixed with other streams and fed to the super heater 240.
• Stream 232c along with the condensed high temperature streams 232e and 233b, are fed to the super heater 240 to superheat the low pressure energy preservation and recycling heating agent (n- octane) vapours stream 239 to a sufficiently high temperature so that when it is compressed in the compressor 231 , there is minimal or preferably no condensation of the heating agent n-octane inside the compressor.
• Liquid heating agent (n-octane) 237 from the corresponding outlet of the heat exchanger 240 is cooled to the lowest possible temperature and is also fed to the heating agent hold tank 235.
• Lower cooling temperature of the liquid n-octane is achieved by utilizing the very low temperature vaporized heating agent n-octane from the working medium condenser 204, which is at temperature of only about 274 K (1 .0 °C), in the other side of the heat exchange surface.
• Volume of the hold tank 235 is also sufficiently large to store the necessary quantities of the energy preserving agent (heating agent) for the smooth and continuous operation of the novel system
• the cold energy preservation and recycling agent n-octane 236 is then withdrawn from the hold tank 235, and depressurized in the facility 236a to a lower level, stream 238, suitable to be used in the heat exchanger 204 to cool and condense the spent working medium ammonia vapours 203a in one stage or in more than one stage.
• the depressurized liquid heating agent n-octane 238 vaporizes (changes phase to vapours) at temperature of about 274 K (1.0 °C) in the heat exchanger 204 and receives the released condensation latent heat energy from the condensing saturated vapours of the spent working medium ammonia 203b which is at temperature of about 280 K (7 °C) on the other side of the heat exchange surface, and accomplish condensation of the saturated working medium to liquid 205.
• n-octane Depressurization of the cold liquid heating agent n-octane causes also the flash vaporization of a small portion of n-octane 239b, which absorbs (compensates) the energy loss of the flashing and decreasing temperature of n-octane liquid -say from temperature of 283 K (10 oc ) to 274 K (1 .0 0C).
• Excess portion of the depressurised liquid working medium 236b which is not required in the heat exchanger 204 (as is explained in the thermodynamics section of the processes), and is at temperature of 274 K (1.0 °C) is fed to the sea water heat exchanger 256 and is vaporized 236c by the effect of higher temperature sea water at about 284 K (12.0 °C) plus. All streams of the low pressure vapour of the heating agent (n-octane) 239a, 239b and 236c are joined in one stream 239 and is fed to the heat exchanger (super heater) 240.
• the low pressure n-octane vapours are heated to a sufficiently higher temperature that when it is compressed in compressor 231 , minimum or preferably no condensation of the heating agent (n-octane) will take place.
• Amount of thermal energy in the said streams 239a, 239b and 236c, is sufficient to super heat the low temperature n-octane stream 239, from 274 K (1.0 °C) to over 355 K (82 °C), which is the desired temperature prior to feeding to the compressor 231 , as will be shown in the modelling example.
• the superheated n-octane vapours stream 230 is fed to compressor 231 to be compressed to the required pressure of stream 232 and repeat the energy preservation and recycling loop.
• the spent working medium ammonia vapour 203 is cooled and condensed in the heat exchanger 204, and even though its saturation condensation temperature is only 280 K (7 °C), it actually represents the hot side of the heat exchanger.
• Liquid and colder energy preservation and recycling heating agent n-octane 238, is withdrawn from the hold tank 235 via depressurization facility 236a, at temperature of 274 K (1 .0 °C) and is fed to the other inlet of heat exchanger 204 and is vaporized by effect of the hotter and condensing working medium ammonia vapours 203 at temperature of 280 K and the heating agent absorbs the condensation latent heat of condensing ammonia.
• the vaporized heating agent n-octane 239a leaves heat exchanger 204 from the corresponding outlet at temperature of about 274 k (1 .0 °C), and the heat exchange side of the heating agent n-octane represents therefore, the cold side of the tube surface of heat exchanger 204.
• the condensation temperature is constant under specific pressure, such as ammonia condenses at temperature of 280 K under the pressure of 5.5077 bar.
• Vaporization temperature of the single component pure material coolant (energy preservation and recycling agent, n-octane) at the opposite side of the heat exchange surface is also constant under specific corresponding pressure, such as vaporization temperature of 274 K, under constant pressure of 0.00466 bar.
• condensation temperature of the working medium will be a range, which reflects concentration of the high boiling solvent water in the condensed mixture at the start and end of the condensation process.
• condensation of the working medium vapours of ammonia-water mixture starts from temperature of 298 K (25 °C) and ends up at temperature 280 K (7.0 °C) under a constant pressure of about 5 bar.
• Such a range can actually provide a better temperature difference (delta T) for the heat exchange process.
• working medium stream (303b) which is a multi component material such as ammonia- water mixture with a specific concentration of water in ammonia
• condensation temperature starts from temperature of about 325 K (62 °C) under the pressure of 0.75 MPa (7.5 bar)
• condensation of the entire stream 303a will be completed at about 294 K (21 °C).
• embodiments of the heat engine 200 comprises feature which include means for storing (holding) liquid working medium 206, means for pressurizing liquid working medium 207, means for the flash separation of the high pressure and high temperature working medium vapours 213 from the liquid working medium 217, means for converting energy of the vapour's pressure to mechanical work 202, means for the heat exchange 204, 209, 21 1 , 215, 202b, 240 and 256, means for energy preservation and recycling agent compression 231 , means for providing mechanical drive 246, means for storing (holding) liquid heat preservation agent 235 and lines or pipes or tubes or other means for conveying the high pressure and high temperature working medium 208, or the spent (waste) working medium 203, or the pressurized heating agent vapours 232 or the liquid heating agent 236, from one component of the heat engine 200 to another component of the heat engine 200 embodying the invention.
• this energy preservation and recycling loop is therefore, to preserve and recycle as much as possible, preferably the entire amount, of the condensing thermal energy (latent heat) from the condensing spent working medium, boost its temperature level and return it to be used and re-used for heating the pressurized and cold liquid working medium ammonia streams 208, 210 and 21 1 to the highest possible temperature and also to vaporize a portion or full amount of the working medium ammonia in the heat exchanger 21 1 , and produce more mechanical work and power from the induced energy into the system.
• the condensing thermal energy latent heat
• the heat engine 200 further comprises an energy preserving system with two sub-loops No 1 and No 2, and can have more than two sub-loops, and each of the sub-loop 416 and 417 and other sub-loops, is an integrated, separate and distinctly operating closed loop.
• Each sub-loop performs a portion of the main loop of absorbing the latent heat of condensation of the spent working medium 203b in the heat exchanger 204 and elevating temperature of the vaporized heating agent A from the level of cold reservoir of vaporization of heating agent (A) stream 238 in the heat exchanged/condenser 204, to the final compressed heating agent temperature of the final sub-loop, in this case heating agent (B) stream 432, at the outlet of compressor 431 , which is the high temperature of the hot reservoir, and is suitable to be used in the heat exchanger/vaporizer 21 1 , to heat and vaporize the single component working medium 210 or rich solvent 310.
• compressor 231 of the sub-loop No. 1 elevates temperature of the vaporized heating agent A stream 239 from the heat exchanger/condenser 204, the cold reservoir temperature, to a pre-selected level suitable interim temperature to be used in the heat exchanger 405 to heat and vaporize heating agent B stream 436d, which is then fed to compressor 431 of the sub-loop No 2 to be compressed to a suitable level pressure and elevate temperature of the outlet stream 432 to the level of the high temperature hot reservoir of the heat engine 200, which is suitable to be used in the heat exchanger 21 1 , to heat and vaporize the pressurized single component working medium 210, and the corresponding outlet stream 212, is fed to the separation flash tank 213.
• the condensed heating agent A stream 233a is fed to the heat exchanger 209 to heat the pressurized liquid working medium 208, and the resulting cooled heating agent A stream 234, is fed to the hold tank 235, and then to the heat exchanger/vaporized 204, to be vaporized by the hotter condensing spent working medium from the turbines 202, and repeat the sub-loop No.1 function.
• the condensed heating agent B streams 436 and 437 are fed to the hold tank 435 and then to the heat exchanger/vaporized 405 to be vaporized by the hotter condensing heating agent A from the compressor 231 and repeat the sub-loop 2 function, Compressor of the energy preservation sub-loop No 1 is powered by the turbine 246 and compressor of the energy preservation sub-loop No 2 is powered by the turbine 446 which receives the high pressure and high temperature working medium stream 445 from the stream 214a, from the super heater 215, and the spent working medium 447 is added to other streams of working medium and condensed in the heat exchanger 204 or 304.
• the heat engine 200 further comprises means to deliver the high temperature vapours of heating agent 501 from the outlet of the energy preservation and recycling system compressor 231 to a heat exchanger or reboiler 221 of the single component working medium or lean solvent circulating loop of the separation flash tank 313.
• Temperature of the condensing vapours of the heating agent should be higher than the required temperature of the single component working medium or lean solvent at the bottom of the flash separation tank 213, by 10 °C to 15 °C to effect efficient heat transfer and boiling of the single component working medium or lean solvent.
• the condensed heating agent 502 is returned and added to the condensed heating agent 232e from heat exchanger 202a to be fed to the heat exchanger 240 (super heater) for cooling down to the suitable lowest level and fed to the hold tank 235 and repeat the energy preservation and recycling loop (heat pump cycle). Operating such a scheme shall be within the boundaries of keeping the overall material and heat balance of the system (cycle)
• the heat engine 200 further comprises an energy preservation sub-loop system (also operating on heat pump principle), to produce and deliver higher level thermal energy to the high pressure and vaporized working medium 214 interring heat exchanger 215 for superheating the single component or multi component working medium.
• the energy preservation sub-loop comprises a booster compressor 602 which receives a stream of the vaporized high pressure heating agent 601 from the outlet of compressor 231 and further compresses it to a suitable higher pressure and proportionally increase condensation saturation temperature of the heating agent 603 at the outlet of the compressor 602.
• the high pressure and high temperature heating agent 603 is fed to the super heater 215, instead of the live medium or high pressure steam, to increase temperature of the working medium 214 to the required level.
• Heating agent 603 condenses in the super heater 215 and exits the said heater 604, which is then added to the condensed streams of heating agent 233 and fed to the heat exchanger 209 for cooling down to the suitable lowest level and sent to the hold tank 235. From the hold tank, the cold heating agent 237 is withdrawn and depressurized to the suitable level and is fed to the heat exchanger 204, and repeats the energy preservation main loop and sub-loop (heating internal cycle).
• Working medium turbine 607 is utilised to provide the necessary mechanical power for compressor 602, and receives a stream of high pressure high temperature super heated working medium 606 and the spent working medium 608 is added to the other spent working medium streams 203 and 247 to be condensed in the heat exchanger 204, and repeat the power generation loop (internal cycle). Operating such a scheme shall also be within the boundaries of keeping the overall material and heat balance of the system (cycle)
• the heat engine 300 further comprises a dual liquid pump 701 , which receives the high pressure lean solvent 702 from the outlet of the heat exchanger 319.
• the high pressure lean solvent drives the dual liquid pump 704 to pump and pressurize a portion of the low pressure rich solvent 705 which is received from the rich solvent hold tank 306.
• the spent low pressure lean solvent 703 leaves the dual liquid pump and is mixed with other low pressure streams 303, 347 and 352 to be fed to the heat exchangers 304.
• the pressurized rich solvent 706 leaves the dual liquid pump and is added to the rich solvent stream 308a and 308b, which are pressurized by the electric pump 308.
• Stream 308a is fed to the heat exchanger 309 while stream 308b is fed to the heat exchangers 319. After these heat exchangers the two streams are combined and fed to the heat exchanger 31 1 and then to the separation flash tank 313.
• the heat engine 200 further comprises a vent 801 from the top or any other suitable point of the working medium hold tank 206, which is used to control pressure inside the single component or rich solvent hold tank.
• the vented vapours of the working medium 801 are fed to the booster compressor 802, which is driven by electric motor but also can be driven by a turbine similar to that of the booster compressor 602 of the embodiment 600 of the heat engine, and increases pressure of the re-compressed vent vapours to a level suitable to be added to the other spent working medium streams 203, 247, 608, etc.
• the controlled reduction of the liquid working medium pressure and hence, temperature of the single component but particularly the rich solvent can be used to improve operation control and efficiency of the novel system.
• the heat engine 200 further comprises a direct fired heat exchanger 900, which is used to superheat the high pressure and high temperature saturated working medium 214 from the outlet of the flash tank separator 213.
• the high pressure and high temperature working medium stream 901 (or 214) is fed to the heat exchanger 900 which is heated by a direct fire of burning some suitable fuel 904 and air 905 to provide the required energy.
• the superheated working medium 902 to the required temperature is fed to the power turbine 202, 246, 607, etc as required by the heat engine.
• This embodiment can supplement and/or substitute the super heater 215.
• the heat engine 200 further comprises a direct fired boiler 1000, which is used to generate suitable pressure steam 1002 to be used to super heat the working medium high pressure and high temperature stream 214 in the heat exchanger (super heater) 215.
• Treated water and condensate 1005 is withdrawn from the hold tank 1004, pumped by the pump 1006 and is fed 1001 to the boiler 1000, which is heated by a direct firing of suitable fuel 1007 with supply of air 1008.
• the generated steam 1002 is fed to the super heater 215 to provide the required energy for superheating the high pressure and high temperature saturated working medium 214.
• Condensed water 1003 is fed back to the hold tank to be treated, pressurized by the pump and repeat the heating loop.
• the heat engine 200 further comprises a heat exchanger (256) arranged to receive higher temperature heating agent vapours 1 105 from compressor 231 and pass through the heat exchanger 256 and condense the heating agent vapours 1 106 by a colder sea water stream 255.
• the condensed heating agent 1 106 is added to the heating agent hold tank 235.
• the hotter sea water stream 257 from the heat exchanger 256 is returned to the ocean or sea.
• the alternative embodiment shown in figure 12 of the heat engine 200 can therefore be a dual function feature of both vaporization of the cold depressurized liquid heating agent (n-octane) from hold tank 235, via depressurization facilities 236a, as described in the report body, and condenser of the compressed heating agent vapours from the compressor 231 , as described above.
• n-octane cold depressurized liquid heating agent
• the embodiment shown in figure 13 of the heat engine 200 comprise means of a multi stage compressor, with knock out tanks for withdrawal and separation of the condensed working medium at the end of each compression stage,
• Materials which are suitable for use as "working fluids" in this invention can be pure components, multi-components or mixtures of components and are selected and aimed for performing functions of either of the two main loop fluids which are;
• thermodynamic properties, operational behaviours and characteristics for one group of materials can be the most undesirable properties and characteristics for materials of the other group (heating and cooling agents), as described below.
• Materials which are suitable to be used working mediums in the mechanical work and power generation loop of the novel system can be:
• Multi component fluid for working mediums which comprises a mixture of two or more low and high boiling materials with favourable thermodynamic properties and wide range of inter-solubility, such as ammonia-water mixture,
• Multi component fluids for working medium which comprises a mixture of various hydrocarbons, various freons, or other materials
• difference between the boiling temperature of the lower boiling working medium component (WM) and solvent is preferably more than 100 degrees K.
• Pure Ammonia, pure water vapours and ammonia-water vapour (gas) mixtures have suitable thermodynamic properties and enthalpy-concentration data and diagrams for pure ammonia, pure water and ammonia-water, under a wide range of pressures and temperatures are readily available in the technical literature and are considered to be reasonably reliable. Therefore, pure ammonia and ammonia-water mixtures have been considered as suitable materials and selected for use in this invention.
• P - is the gas pressure at the start of intended process
• V - is the gas volume at the start of intended process
• the adiabatic expansion exponent k is expressed in terms of ratio of the specific heats of gas under constant pressure (C P ) to specific heat of the said gas under constant volume (C v ), as follows:
• value of the exponent (k) deceases and can be significantly lower than 1 .315.
• value of (k) increases to more than 1 .315, for both ammonia and water vapours. This characteristic is very useful in extracting more work and energy from the expanding ammonia and water vapours (gases) through the turbines and is explained in thermodynamic analysis section of this report.
• Suitable materials for "Heating Agents” The use of energy preservation and recycling system (heat pump principle) in the novel power plant models is aimed at preserving and recycling as much as possible and preferably the entire amount of the induced thermal energy within the operation cycle (saving energy).
• the amount of energy which can be economically preserved and recycled within the proposed power system depends on many factors, but particularly depends on the physical and thermodynamic properties of the employed heating agent and the selected operation conditions of the loop, such as:
• exponent (n) should be as low as possible, and preferably below 1 .0655, to achieve better system efficiency (as is explained in the thermodynamic analysis section),
• the heating agent has high latent heat of vaporization of -say more than 380 kj/kg (90.77 kcal/kg) or higher, at the cold reservoir temperature,
• the freezing point of the selected heating agent should be sufficiently (at least few degrees K) below the temperature of the cold reservoir to avoid any unexpected system freezing
• Required operation temperature range for elevating energy from the cold reservoir temperature ⁇ ⁇ , to the hot reservoir temperature T hot , - Required range of temperature increase should be such that the energy preservation and recycling system compressor "Coefficient of Performance COP" (heat pump principle) is preferably maintained at above 7,
• thermodynamic properties there are many materials with suitable thermodynamic properties, which can be used as heating and cooling agent such as:
• thermodynamic properties of these materials for selection as energy preserving agents are highly desired and selected to be contrasting with the same thermodynamic properties of working mediums of the mechanical and power generation loop (ammonia and water vapours).
• value of the exponent (k) or (n) in the equation of state of vapours and gaseous is highly desired and selected to be contrasting with the same thermodynamic properties of working mediums of the mechanical and power generation loop (ammonia and water vapours).
• n-octane has suitable thermodynamic properties and has been selected (as example) for use as the heating agent in this invention.
• the invention embodiments shown in figure 4 are for the single component working medium and are taken as the example reference and basis for the novel system (power plant) calculations and analysis.
• An example of the suitable single component working medium is "pure ammonia" and has been selected as the working medium (WM) for the system analysis and calculations.
• An example of the suitable single component energy preservation and recycling system material (heating agent HE) is n-octane and has been selected for the system analysis and calculations.
• the calculations are made for a selected flow rate of the working medium ammonia through the turbine (or turbines) of one (1 .0) kg/s. This is also the flow rate of ammonia through all other components of the mechanical work and power generation loop.
• an example set of the required suitable and independent operation parameters and conditions has also been selected for the working medium ammonia progressing through the mechanical and power generation loop of the power plant.
• the corresponding required flow rate and suitable operation conditions of the energy preservation and recycling agent n-octane (heating agent) through each joint piece of equipment of the heat engine 200 between the two loops, is calculated and fixed to satisfy the flow rate of 1 .0 kg of working medium ammonia, taking into consideration parameters of ammonia at the inlet and outlet of each involved piece of equipment.
• Flow rate and suitable operation conditions of n-octane through the other pieces of equipment which are specific to only energy preservation and recycling loop, has been calculated and adjusted to provide a reasonable "example" of the novel power plant operation and means to complete the closed loop and conduct the required evaluation.
• P 2 is the gas pressure at the end of compression process
• V ! is the gas volume at the start of compression process
• V 2 is the gas volume at the end of compression process
• T 2 is the gas temperature at the end of compression process
• n Ln(P 2 /P,)/Ln( ,N 2 ) Eq 5
• Equations 3 and 4 express conditions of adiabatic and also isentropic expansion or compression of the ammonia vapours, as the process takes place without energy introduction into the expanding system from outside and therefore there is not expected a change of it's overall entropy
• any assumed set of operating conditions and parameters which is considered suitable for the mechanical work and power generation loop, will dictate the corresponding set of operation conditions, the size and operation mode of the energy preservation and recycling loop and is therefore, discussed first.
• T-s temperature-entropy diagram of pure ammonia and regions of its phase existence and inter-changes, which are:
• the diagram shows that while entropy of liquid ammonia increases with increasing saturation temperature line A-B-T cr , entropy of the ammonia vapours decreases with increasing saturation temperature, line D-C-T cr . There is expected therefore only one saturation temperature (point) where entropy of both liquid and vapour phases of ammonia converge and are equal, and that point is at the critical temperature (T cr ). However, if the fully vaporized ammonia is superheated from any point on the saturation vapour line T cr -C-D, entropy of the superheated ammonia gas increases with increasing temperature.
• Entropy Path of the superheated ammonia gas moves (flows) in the same direction (and somehow parallel) with the entropy path of liquid ammonia and diverges widely with entropy path of the saturated vapours.
• the formed intersect angel of the superheated and saturated vapours entropy lines is generally obtuse for ammonia and close or much wider than 90° degrees.
• Such diverging entropy lines of the superheated and saturation phases of ammonia gas elongate the isentropic expansion path and, if superheated to a sufficiently high temperature, create the opportunity for extracting more energy from those expanding gases.
• These are typical thermodynamic characteristics of the vapours and gases (materials) of low molecular structure (fewer atoms) and weight, such as, water vapours, ammonia, methane, carbon monoxide, etc.
• thermodynamic properties of ammonia are utilised for power generation from the expanding ammonia gas and vapour from the selected high pressure of 7.135 MPa (71.35 bar) to the lower pressure of spent vapours of 0.55077 MPa (5.5077 bar) through the turbines 202 figure 3, which can be of one stage or multi stage turbine.
• thermodynamic power generation closed loop which includes:
• ammonia turbine is selected as a two stage type with interim superheating, and the turbine produces mechanical work and generates electrical power from both stages of ammonia expansion.
• Saturation temperature of ammonia under 5.5077 bars is 280 K
• Saturation temperature of ammonia under 71 .35 bars is 380 K
• n 1 .1532568
• Isentropic efficiency ( ⁇ , 3 ) is (about):
• the deficit amount of energy is satisfied from the released latent heat of condensation of the condensed portion of ammonia vapours and the process continues to the pre-selected outlet back pressure of ammonia vapours from the turbine, in this example 5.5077 bar.
• Coinciding the final expansion temperature of ammonia with the theoretical calculated temperature at 100% exponent value means full 100% utilisation of the expansion process and no losses to the effect of working medium ammonia condensation inside the turbine.
• Temperature drop (delta T) during the isentropic expansion of ammonia from 71.35 bar to 5.5077 bar, is:
• the involved isentropic expansion process and the expansion temperature range of ammonia gas is significantly elongated and widened. If such expansion conditions can be provided in the actual industrial practice, it shall result in extraction of significant amount of net energy from unit weight of the expanding ammonia gas. Mechanical work extraction from the full amount of the expanding ammonia gases continues to the end of the process without any condensation, volume reduction (shrinkage) and entropy split-disruption between liquid and vapour phases.
• th ) of the system is:
• ammonia vapours are compressed (isentropic), there is expected a higher temperature of the compressed materials above the saturation temperature of the final compression pressure. If ammonia is compressed from the saturation pressure of -say 5.5077 bar (point D on the T- s diagram figures 16 and 17) then the compression path will only be along the superheating line D-E and the final temperature of compression will correspond to a saturation pressure on the line C-D. If for example, the final compression pressure is 71.35 bar, then the final compression temperature of ammonia gas will be 496.5 K, which is the expected superheating level and well above the saturation temperature of 380 K, per the equation:
• ammonia vapour is compressed (isentropic) from the pressure of 5.5077 bar (figure 17 point D) to 71 .35 bar
• the compression process can take two paths, which are: a- Direct isentropic path from the saturation pressure point D of 5.5077 bar which will be along the line D-E and ammonia is superheated at any of the points on the path D-E.
• a- Direct isentropic path from the saturation pressure point D of 5.5077 bar which will be along the line D-E and ammonia is superheated at any of the points on the path D-E.
• the path along the saturation line D-C which requires continuous addition (injection) of liquid ammonia into the compressor to suppress the superheating effect of compression.
• a continuous amount of liquid ammonia is vaporized to absorb the superheating energy and then these vapours will also be superheated in the
• Exact amount of liquid ammonia which is required to be injected into the compressor during the isentropic compression process, to suppress the superheating of the compressed ammonia vapours while reaching the final pressure of 71 .35 bar and the saturation temperature of 380 K (point C), is equal to the amount of ammonia which would condense if the final amount of the high pressure and saturated ammonia vapours at 71.35 bar (at point C), are expanded back to the pressure of 5.5077 bar (at point D).
• Starting conditions of required injection liquid ammonia, pressure and temperature should be same as the vapour conditions of 5.5077 bar pressure and temperature of 280 K. There is therefore a significant increase of ammonia vapours amount (weight) from the initial vapour amount at the start of compression process.
• the vapour ammonia point D will be about 0.74 kg and the amount of liquid (condensate) ammonia at point G about 0.26 kg.
• the amount of ammonia vapours will be one kg.
• the generated power is:
• This loop is the most crucial novelty part of the proposed power system, and the selected heat agent as the working fluid for this loop is n-octane.
• This loop when joined with the power generation loop (superimposed on) shall form the proposed novel "Atalla Harwen Cycle".
• FIGS 21 , 22, 23, 24, 25, 26, 27, 28, 29 and 30 show different variations of temperature-entropy (T-s) diagram of n-Octane.
• T-s temperature-entropy
• Increasing entropy of the vapour phase of n-octane with increasing temperature is in contrast with same property of ammonia and other low molecular weight vapours and gases such as water vapour, methane, carbon monoxide, etc. who's vapour entropy doctresses with increasing temperature figure 16, line D-C-T cr (as discussed above in the working medium section).
• the contrasting directions of entropy of ammonia and n-octane vapours with increasing temperature entails that they will demonstrate different thermodynamic behaviour and characteristics during compression and expansion vapours and gas processes of these two materials.
• n-octane vapours are allowed to undergo isentropic expansion from a higher saturation pressure level, such as point C figure 22, to a lower pressure, then the isentropic expansion process will also progress along the vertical direction from any point on the vapour saturation line B-C to near Tcr, such as point C, and is within the all vapour superheated status area of n-octane. Hence, the expansion process will take the path from point C to Point B1 and will terminate at point a on the vertical line such as point B1 , if the final expansion pressure is selected as the saturation pressure of point B.
• n-octane vapours results in their relative cooling from the top temperature, but they will be at the superheating state at the final expansion pressure and they will be at a much higher temperature as compared with the saturation temperature of the final expansion pressure at point B.
• This behaviour of n-octane vapours is in contrast to ammonia behaviour during expansion process, which as was shown, results in significant cooling and condensation of ammonia vapours if expanded from the saturation line point C Figures 16 and 17.
• the contrasting behaviour and effect of expansion of vapours of the two materials can be explained from the adiabatic equation of state No 1 , of gases and vapours and application to n-octane also and compare with earlier calculation results of ammonia.
• thermodynamic behaviour and characteristics of the heating agent n-octane during compression and expansion processes through the energy preservation and recycling loop compressor, with the corresponding temperature changes, will be described and analysed and results will be compared with those of the ammonia behaviours as applicable.
• Process temperature changes of n-octane with pressure are the main indications and criteria of the system operation and possible economics, and are highly dependent on its thermodynamic properties, per the equation of state:
• thermodynamics of the compression process are defined and analysed, per the equation state of gases and vapours applied for n-octane, as follows:
• the saturation temperature of n-octane vapours at pressure of 1 .2218 bar is 405 K, which indicates that there is a large deficit of energy in the system to elevate temperature of the compressed materials (n-octane vapour-liquid mixture) to the required 405 K and is not provided by compressor work. There must be therefore, a supplement internal source of energy (reorganization) within the system.
• Figure 22 shows that during the isentropic compression of n-octane from the pressure of 0.00466 bar (point B), to 1 .2218 bar along the path B-C1 , there is significant condensation of n-octane (G con ) which is about 47.43%, calculated from entropy change:
• - Area No 2 Represents the latent heat of vaporization, which is added to the unit weight of n-octane in the heat exchanger (condenser) 204, figure 3, and is the energy status of the fully vaporized and saturated n-octane at the entrance to the energy preservation and recycling compressor 231 , when by-passing the super heater 240 and the start of compression process,
• - Area No 4 Represents the latent heat of the condensed portion of n-octane at the outlet of the energy preservation and recycling compressor 231 , which does not go out as part of energy of the condensed portion of n-octane but actually migrates to the vapour portion of n-octane
• - Area No 5 Represents the added energy to vapour portion of n-octane during compression, and comprises two sources of energy which are:
• Area No 1 represents energy of the liquid n-octane, heating agent, status at conditions of entrance to the heat exchanger 204, which is at the lowest temperature (cold reservoir temperature) of the heat engine 200 operation, and then enters the heat preservation and recycling system compressor 231 , and exits compressor 231 in the proportionate amounts with:
• This amount of energy of the heating agent is associated with the n-octane status at the entrance to the heat exchanger 204 of the low temperature reservoir and does not change while the material n-octane circulate within the energy preservation loop, and when the heating agent completes the full circulation loop (cycle) and reaches back to the entrance of heat exchanger 204, n-octane is always at the same status and is at the low temperature reservoir reference level.
• Compressor work (energy) (W com ) input into the n-octane vapours during compression can be defined from the energy representation areas,:
• Compressor work (W com ) is also defined from the difference between enthalpy of the unit weight of n-octane into the compressor 231 , and enthalpy of same unit weight of n-octane out of the compressor as follows: (enthalpy h of n-octane into the compressor and of each component out from the compressor 231 is suffixed by the relating area number of figure 23):
• the required compression work per kg of n-octane, to absorb the condensation latent heat (rejected) of spent ammonia and elevate its temperature from outlet of the turbine 202, for re-use inside the system heater 21 1 , is expected to be relatively high.
• To absorb the latent heat of condensation of one kg/s of ammonia will require about 3.6 to 3.8 kg of n-octane, and the huge amount of condensation of n-octane inside compressor, may make this option not realistic or practical.
• the required specific energy per one kg of ammonia is:
• Maximum required work (W cmax ) of the energy preservation and recycling system compressor is expected therefore to be, when the vapour phase is exhausted and entire amount of n-octane vapours are condensed at point E.
• Maximum work (W cmax ) for compressing one kg of n-octane vapours at the inlet into the compressor can be calculated from enthalpy change of n-octane from point B (full vapour phase h B ) to point E (full liquid phase h E ), on the constant entropy line, and is:
• h - is the n-octane enthalpy kj/kg
• U - is the n-octane internal energy kj/kg
• V - is the n-octane volume m 3
• the calculated large percentage of condensation inside the compressor 47.43 % may also be difficult to handle in one compression stage.
• gas and vapour compressor's smooth operation and work is mostly conducted without significant condensation of the compressed fluid (agent) inside the compressor, which can cause damage to the compressor parts.
• condensation tolerances which manufacturers provide along with the operation data for each type and models of their compressors.
• Some compressors can operate with up to 16% condensation of the heating agent inside them.
• practical technical measures need to be introduced and/or supplemented to ensure a smooth and reliable operation of the compressor.
• an example of the suitable operation conditions is selected to condense the spent ammonia vapours from turbine 202, which is at 280 K (7.0 °C) in the heat exchanger/condenser 204, by utilizing and vaporizing a suitable hearing agent (in this example n-octane) on the other side of the heat exchange surface.
• a suitable hearing agent in this example n-octane
• This compression option is performed from n-octane conditions of the saturation line B-C-T cr , and is selected from point B figures 22 and 23.
• Saturated n-octane is fed to the compressor under a pressure of 0,00466 bar and at temperature of 274 K (1.0 °C) and is compressed to the pressure of 1.2218 bar which corresponds to the saturation temperature of 405 k (132 °C).
• compression process of n-octane can be performed by:
• Required specific compressor work per one kg of n-octane is calculated from the enthalpy of one kg of n-octane at the inlet into and outlet from the compressor and is, (and per energy representing areas of figures 22 and 23) and conditions of n-octane at points B and C, figures 22 and 23:
• n-octane (G oct ) required amount to vaporize one kg of ammonia in the heat exchanger 204 is calculated from the latent heats of condensation of ammonia and vaporization of n-octane:
• the high energy (work) requirement for the system compressor is due mainly to the fact that all the condensed n-octane inside the compressor exits at the end of compression process, regardless of the involved internal compression stages, at the same temperature as the vapour temperature of 405 K (132 °C).
• the condensed n-octane particularly at the initial stages of compression requires more energy to be heated to the final compression temperature, and the total amount of the required heating energy for the condensed portion in this example, is:
• the released latent heat (energy) of the condensed n-octane is split between heating the condensate portion to the final compression temperature and migration to the vapour portion which supplements the compressor work, as follows:
• This compression option is performed from n-octane conditions of the saturation line B-C-T cr , and is selected from point B figures 22 and 23.
• Saturated n-octane is fed to the compressor under a pressure of 0,00466 bar and at temperature of 274 K (1.0 °C) and is compressed along the saturation line B-C to the pressure of 1 .2218 bar which corresponds to the saturation temperature of 405 k (132 °C).
• Theoretical amount of n-octane which will condense along the saturation line B-C, while compressing and continuously withdrawing the condensed portion of n-octane is expected to be significantly less than 47.43 %, and is in the range between 24% to 47%.
• Latent heat (L T h) which can be saved per one kg of the compressed n-octane and used to supplement the compressor work, while the compression progresses along the saturation line B-C, figure 25, is expected therefore to be significantly reduced and to be within the range of about 24% to 30%. Then the expected portion of the latent heat saving and migration to supplement the compressor work is assumed from condensation of only about 25% of input n-octane inside the compressor, while n-octane is compressed along the vapour-liquid equilibrium line B - C, figures 25, and its temperature is increased to 132 °C.
• the specific required power is expected therefore, to be between -80.342 kj/kg (-19.193 kcal/kg) and - 92.331 kj/kg (-22.057 kcal/kg), and are the two extreme operation cases on the two sides of the 4 stage compression process.
• FIGS 26 and 27 show the temperature-entropy (T-s) diagram of the heating agent n-octane.
• the diagram also show n-octane thermodynamic operation closed loop of energy preservation and recycling with the case (option) of superheating n-octane vapours in the heat exchanger 240 Figure 3, prior to feeding to the energy preservation and recycling compressor 231 .
• the said operation closed loop includes;
• n-Octane vapours are fed to the super heater 240 and heated to a temperature of about 355 K (82 °C) also under constant pressure and then fed to the compressor 231 to be pressurized to a preselected suitable pressure (in this case 0.12218 MPa, 1 .2218 bar), under which the corresponding condensation saturation temperature of n-octane is lifted to 405 K.
• a preselected suitable pressure in this case 0.12218 MPa, 1 .2218 bar
• n-octane vapours When the low pressure and low temperature n-octane vapours are superheated in the heat exchanger 240, it increases both the enthalpy and entropy of those vapours. Importantly also, specific heat of the low pressure n-octane from point B figure 26, under constant pressure (C p ), is significantly higher than the specific heat of the saturated n-octane vapours, which increases along the saturation line B-C, and the superheating process path is expected to be along the path (line) B-B1. Selection of the top temperature of superheating process of n-octane at point B1 is important to:
• Superheating Line B-B1 is expected therefore, to intersect with all the theoretical isentropic compression lines of n-octane on the path from point B to point B1 .
• the top superheating temperature of n-octane is selected and controlled at a level where the entropy of the superheated n-octane vapours at the top heating temperature, point B1 , is at least very close/equal to the entropy of the saturated n-octane at point C, or little higher.
• Entropy of n-octane at this superheating temperature 355 K corresponds and is equal to entropy of n-octane at the saturation temperature of n- octane at temperature 405 K (132 °C).
• the "intersect point" of superheating lines B - B1 and the isentropic compression path (under constant entropy), which is the vertical line through point C, is the point B1 .
• Higher superheating temperature will push the intersect point B1 higher up along the superheating line B-B1 - B2, Figure 28, and can also be suitable for the system operation and compressor work reduction.
• the vertical process path line is expected to intersect with the saturation line at point C, where the pressure is the required top pressure at the corresponding equilibrium status of n-octane full vaporization at point C under the pressure of 0.12218 MPa (1.2218 bar) and temperature of 405 K (132 °C).
• Equation of state of gases and vapours process with no energy exchange with outside environment is:
• the calculated temperature is actually higher than the assumed temperature at point B1 of 355 K, for calculation of the required compressor energy (below), which means that calculation of the required compressor power is on the conservative side.
• the compression line is expected to intersect with the vapour-liquid saturation line at point C.
• Such a compression process under constant entropy is "isentropic" process and energy input from the compressor is required to increases temperature of the compressed n-octane vapours from 355 K to 405 K.
• the expected work input from the energy preservation and recycling compressor (heat pump principle) (W cs ) per one kg of n-octane is (referring to enthalpy h of n-octane, at the relevant points B1 and C from figures 26 and 27 ) is:
• This amount of the required compressor work is significantly lower than the required compressor work input in the cases of single stage or multi stage compression, or along the saturation line B-C figure 25, without superheating.
• the introduced superheating energy into the n-octane vapours in the heat exchanger 240 is aimed to compensate for: - The need for n-octane partial condensation inside the compressor, to sustain the isentropic compression process,
• C sp Specific heat (C sp ) of n-octane vapours under those conditions of isentropic compression (mild conditions) is relatively low, due to the fact that there is not required energy input for entropy increase and volume of the superheated n-octane gas tends to shrink fast under the effect of pressure impact.
• the rate of entropy increase of the superheated n-octane with temperature line B - B is higher than the rate of entropy increase of the saturated n-octane line B-C, and the superheating process therefore is moved slightly to the right of the equilibrium line B -C, and the intersect point of these two entropy increase lines with temperature, forms a relatively sharp acute angle.
• Figures 26, 27 and 28 show that superheating of n-octane in this manner, has actually truncated the required isentropic compression process path significantly to a very short distance B1 - C, which is also the isentropic expansion path line of the n-octane if expanded from point C and from pressure of 0.12218 MPa (1 .2218 bar) to a pressure of 0.000466 MPa (0.00466 bar).
• the intersect point of the two lines forms therefore a much wider obtuse angel than the case of n-octane, and can be significantly wider that the straight angel.
• This behaviour of ammonia is actually a desired property, and for all those materials which are used as working mediums for power generation.
• the elongated isentropic path provides the opportunity to extract more energy from the expanding vapours such as ammonia.
• Isentropic efficiency of ammonia expansion process is lower than 100% and the net extracted energy is less.
• n Constant , and:
• PV n Constant
• the compressor efficiency in supplementing its work by utilizing n-octane thermodynamic properties and the combined energy sources to increase the compressed n-octane temperature from 274 K to 405 K, without involving material condensation in the compressor is about:
• the most important task (criteria) for any operating power generation plant to increase overall efficiency of the system is to maximize the use of the induced energy into the system for power generation and minimize or preferably eliminate heat (energy) rejection to the outside environment, particularly from the spent working medium to the employed coolant.
• the proposed novel heat engine 200 (figure 3) to increase efficiency of the plant, is to properly address this heat rejection issue and minimize or preferably eliminate the energy rejection from the spent ammonia after the outlet from the turbine 202, and avoid the use of an outside coolant.
• n-octane liquid to be vaporized in the cold side of the heat exchanger 204 under pressure of 0.00466 bar and at temperature of 274 K (1 .0 °C), to absorb the released above enthalpy (latent heat condensation) of ammonia, is:
• net amount of energy elevated from the cold temperature reservoir 274 K to the high temperature reservoir of 405 K and used in the system is:
• This energy is a relatively high amount and is also significantly higher than the required energy to heat one kg of ammonia from 280 K to 390 K and vaporize it under pressure of 7.135 MPa (71.35 bar), and further heat it to 400 K, which requires about 1237 kj/kg (295.5 kcal/kg).
• the net power (W t ) in MW which is generation per the ammonia flow rate of one kg /s through turbines and allowing for another system efficiency of 85%, is:
• the energy sources can be considered as environmentally friendly and also as green energy, which should be a positive indication and critera for the novel power plants employing this technology.
• Coefficient of performance (COP) of the energy preservation and recycling compressor (heat pump principle) at these operation conditions is calculated as follows, and assuming that:
• Modelling and calculation is based on features of the heat engine 200, with the embodiments shown in the configuration diagram (figure 3), and all equipment and material flow streams being given like reference numerals, and the assumed working medium ammonia flow rate of one (1.0) kg/s through the power loop of the novel plant.
• the main aim of the example and modelling is to organise, calculate, analyse, define and confirm: a- Mass balance of the individual components (pieces of equipment) and the overall operational system,
• n-octane Flow rate of n-octane is controlled and set to provide the corresponding necessary heat and mass balances of each joint piece of equipment with the working medium ammonia and its flow rate of one (1 .0) kg/s,
• n-Octane (with little excess) through the energy preservation and recycling loop is set at 3.8 kg per one kg of ammonia, ii.
• Liquid ammonia pumping pressure to the vaporized and superheated ammonia at the inlet into the turbine and spent ammonia pressure from the turbine are randomly selected to suit the operation criteria, and are:
• Superheating temperatures of high pressure vaporized ammonia are selected to eliminate condensation of ammonia inside the turbine during expansion processes, and they are:
• n-octane is also selected so that minimal or no condensation of material takes place during compression process, and is at:
• a heat engine for producing mechanical work using a working medium comprising:
• a. a first heat exchanger (204) comprising:
• the first heat exchanger is arranged to transfer energy from the working medium to the heating agent to at least partially vaporise the heating agent; and iii. a first output (o1 ) for outputting the vaporised heating agent;
• a compressor (231 ) coupled to the first output of the first heat exchanger for compressing the vaporised heating agent, wherein the compressor compresses the heating agent thereby changing at least a portion of the vaporised heating agent from a vapour state to a liquid state;
• a second heat exchanger (204) comprising:
• a heat pump for use with a heat engine for producing mechanical work using a working medium comprising:
• a. a first heat exchanger (204) comprising: i. a first input (i1 ) for receiving a substantially vapour working medium output from an energy extraction device;
• a compressor (231 ) coupled to the first output of the first heat exchanger for compressing the vaporised heating agent, wherein the compressor compresses the heating agent thereby changing at least a portion of the vaporised heating agent from a vapour state to a liquid state;
• a second heat exchanger (204) comprising:
• thermoelectric heating agent is selected from the group comprising n-Octane, n-Heptane, Butylformte, Diethylamine,
• the first heat exchanger is arranged to transfer energy from the working medium to the heating agent at a substantially constant temperature and preferably at a substantially constant pressure.
• the second heat exchanger is arranged to transfer energy from the heating agent to the working medium at a substantially constant temperature and preferably at a substantially constant pressure.
• a heat engine for producing mechanical work using a working medium comprising:
• a. a first heat exchanger (204) coupled to a working medium and to a heating agent, wherein the heat exchanger is arranged to extract energy from the working medium and to vaporise at least a portion of the heating agent using the extracted energy;
• a heat pump for use with a heat engine for producing mechanical work using a working medium comprising:
• a heat engine or a heat pump according to any preceding clause arranged to operate so that the working medium operates in a temperature range of approximately 0 to 220 degrees Celsius.
• Table 1 shows the modelling program components, interaction and calculation results of each individual operation piece of equipment which together form a full one cycle of the heat engine operation, based on the selected basic assumption set, and are repeatable for any further number of cycles.
• the data can also be approximated and proportionate for any different flow rates of the working medium ammonia and operating conditions.
• the table shows the following results:
• the proposed novel power generation heat engine (plant) produces reasonable amount of net energy from the induced energy into the system and achieves high efficiency of over 57 %,
• any required capacity plant can be designed and manufactured within the metallurgical and mechanical limits of the employed materials. For example, if a plant capacity of -say 100 MW is required, then the ammonia flow rate (G amm ) through system is expected to be (approximately):
• volumetric flow rate This is not a very high flow rate of ammonia, particularly volumetric flow rate, as the density of the spent ammonia at the end of expansion is about 4 kg per cubic metre, and the volumetric flow rate is:
• volumetric flow rate of the low pressure steam under say 0.15 bar (abs) is expected to be:
• Operation conditions can be further optimized and tuned to suit other:

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